Free flow aerosol valve

ABSTRACT

An aerosol valve having a valve stem and compression spring geometry that create shorter flow paths, have fewer changes in flow direction, and passageways with large cross-sections to reduce resistance and back pressure is disclosed. The aerosol valve minimizes agglomeration of solids in the flow paths and reduces product failures. A method of using the aerosol valve is also provided.

BACKGROUND OF THE DISCLOSURE

1. Field of Disclosure

The present disclosure is related to the field of aerosol delivery ofhigh-solids product formulations. More particularly, the presentdisclosure relates to an aerosol valve having a valve stem andcompression spring geometry that create shorter flow paths/fewer changesin flow direction to minimize agglomeration of solids in the flow pathsand thereby reduce product failures.

2. Description of Related Art

Valve structures for product formulations that have a high solidscontent can fail due to agglomeration of the solids in the flow passagesin the internal space of the valve stem housing. Existing designs ofsuch valves typically employ flow paths that have long, narrow channels,abrupt changes in flow direction, and areas of recirculation flow any ofwhich can cause the solids in the product formulation to agglomerate andclog the flow paths.

As used in this application, agglomeration (or any of its forms) is usedinterchangeably with clumps (or any of its forms) without a change inmeaning.

Also, existing aerosol valves have a compression spring that is fullycompressed (i.e., the individual coils are pressed together) when thevalve stem is fully pressed by the consumer to spray the product.However, the compressed coils act as a barrier to the productformulation that is passing upward, and so forces the productformulation to follow a flow path that is nearly entirely on the outsideof the fully-compressed spring, since there is little or no spacebetween the individual coils that allow the product formulation to flowin the space in the center of the spring.

SUMMARY OF THE DISCLOSURE

The present disclosure is an aerosol valve that provides a free flowaerosol delivery of high-solids product formulations with reducedagglomeration and product failure from clogging.

The aerosol valve of the present disclosure includes a valve stem thathas large cross-section passageways that allow the product formulationto flow directly from the dip-tube through the center of the compressionspring. This configuration allows the product flow to be gentlydeflected around the valve stem, which reduces back pressure(resistance).

The valve stem and compression spring geometry of the present disclosurecreates a shorter flow path, and a flow path that fewer changes in flowdirection, as compared with conventional aerosol valves.

The valve stem of the present disclosure also has large cross-sectionflow passageways that minimize drag of product flow in the passageways.

These shorter, large cross-section, non-tortuous flow paths of theaerosol valve of the present disclosure minimize agglomeration of solidsin the flow paths, and reduce product failure from blockage of the flowpaths, even when used for difficult high-solids product formulations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 (Prior Art) is a conventional aerosol valve in full stroke,illustrating the flow paths around the outside of the springs.

FIG. 2 is a side view of an exemplary embodiment of an aerosol valve ofthe present disclosure.

FIG. 3 is a cross-section of the aerosol valve in FIG. 2 in a closed(resting) position.

FIG. 4 is a three-quarters-perspective view of the cross-section of theaerosol valve in FIG. 3 in a closed (resting) position.

FIG. 5 is a perspective view of an exemplary embodiment of a valve stemof the present disclosure.

FIG. 6 is a bottom view of the valve stem in FIG. 5, illustrating thecross-shaped configuration of the four (4) flow passageways.

FIG. 7A is another perspective view of the valve stem in FIG. 5, butadding the compression spring to show its position in relation to thefour (4) flow passageways and aerosol valve. FIG. 7B is the identicalview shown in FIG. 7A, with shading to clearly show the compressionspring.

FIG. 8A is another bottom view of the valve stem in FIG. 6, but addingthe compression spring to show its position in relation to the four (4)flow passageways and aerosol valve. FIG. 8B is the identical view shownin FIG. 8A, with shading to clearly show the compression spring.

FIG. 9 is a perspective view of a cross-section of the aerosol valve inFIG. 2 in mid-stroke, illustrating primary and secondary flow paths,upon partial compression of the compression spring.

FIG. 10 is a side view of a cross-section of the aerosol valve in FIG. 2in full stroke, without showing the flow paths.

FIG. 11 is a perspective view of a cross-section of the aerosol valve inFIG. 8 in full stroke, illustrating the primary and secondary flowpaths, upon full compression of the compression spring.

DETAILED DESCRIPTION OF THE DISCLOSURE

FIG. 1 is a conventional aerosol valve generally represented byreference numeral 10. Valve 10 is illustrated in FIG. 1 in full stroke,illustrating the long, tortuous flow path of the product formulationaround the outside of the compression spring before the formulation isable to enter the center hole of the valve stem.

Aerosol valve 10 includes a dip tube 12, valve stem 16, valve stemhousing 18, mounting cup 20, seal 22, and compression spring 32. Valvestem 16 is enclosed in valve stem housing 18. Valve stem 16 has a pairof apertures (not shown in FIG. 1) through which a pressurizedhigh-solids product formulation passes in order to enter center hole 24of valve stem 16. Mounting cup 20 orients and stabilizes aerosol valve10 in its proper position on the product. Valve stem 16 contactscompression spring 32 at contact point 26.

Compression spring 32 exerts an upward pressure on valve stem housing18, which is pressed against seal 22 that is located on the inner aspectof mounting cup 20. Valve stem 16 has an upper portion that protrudesthrough seal 22 and mounting cup 20, and which is pressed by theconsumer to spray the product formulation.

When valve stem 16 is pressed down by the consumer to spray the product,the product formulation flows upward through the internal space of valvestem housing 18 in a flow path 30.

As shown in FIG. 1, compression spring 32 is fully compressed, pushingtogether the individual coils of compression spring 32 so there islittle or no space between any of the individual coils. In thisconfiguration, the coils of compression spring 32 act as a barrier tothe space that is inside the compression spring, requiring the productformulation to travel upwardly by a long path through valve stem housing18 almost entirely along the outside of compression spring 32. Thislong, tortuous primary flow path 30 increases the probability that thesolids in the product formulation will agglomerate and clog the flowpath, causing the passage of the product formulation in the flow path tobe slowed or blocked altogether, leading to product failure.

FIGS. 2 through 9 illustrate an exemplary embodiment of an aerosol valve40 of the present disclosure. Referring to FIGS. 2 to 4, aerosol valve40 includes a dip tube 42, compression spring 44, valve stem 46, valvestem housing 48, mounting cup 50, and seal 52. Valve stem 46 is enclosedin valve stem housing 48. Valve stem 46 has a valve stem aperture 58through which a pressurized high-solids product formulation passes inorder to enter center hole 54 of valve stem 46. Mounting cup 50 orientsand stabilizes aerosol valve 40 in its proper position on the product.Valve stem 46 contacts compression spring 44 at contact point 56.

Compression spring 44 exerts an upward pressure on valve stem housing48, which is pressed against seal 52 that is positioned on an inneraspect of mounting cup 50. Valve stem 46 has an upper portion thatprotrudes through seal 52 and mounting cup 50, and which is pressed bythe consumer to spray the product formulation.

Seal 52 is a flexible material that seals the space between mounting cup50 and valve stem housing 48. Seal 52 is preferably made of rubber orsimilar flexible material. Seal 52 is preferably shaped as a gasket. Aseal between seal 52, valve stem housing 48 and mounting cup 50 occursby compression during crimping of cup 50. Pressing on valve stem 46 cansomewhat deform the gasket-like seal between seal 52 and valve stemhousing 48 as well as between seal 52 and mounting cup 50.

Dip tube 42 is the access point for the stored product formulation inthe container (not shown) to aerosol valve 40.

Aerosol valve 40 has fewer abrupt changes in flow direction, as comparedwith the flow paths of aerosol valves in the prior art. This reduces thepropensity of the solids in the product formulation to agglomerate inthe flow paths, by providing fewer loci at which the particles mayaccumulate, and thereby reduces product failures.

FIGS. 5 and 6 illustrate an embodiment of valve stem 46 having four (4)passageways 64, 66, 68, 70 that are perpendicular to each other.Passageways 64, 66, 68, and 70 are large in cross-section to minimizedrag and thereby reduce agglomeration of the solids in the productformulation as the product passes through, reducing the incidence ofproduct failure.

The passageways readily allow the product formulation to flow directlyfrom dip tube 42 through the center space inside compression spring 44(shown clearly in FIGS. 3 and 4), and to be gently deflected aroundvalve stem 46. Valve stem 46 is preferentially a thinned valve stembody. These structures and configuration reduce back pressure(resistance) to the flow of the product formulation before it reachesvalve stem aperture(s) 58. This is an advantage over conventional valveflow paths, which require abrupt changes in flow direction and passagethrough long, narrow channels prior to arriving at the valve stemapertures.

Aerosol valve 40 preferentially forms the largest possible flow pathcross-sections that are viable, given the constraints of the valve stemhousing, compression spring geometry, and valve stem molding capability(for strength and moldability). In an exemplary embodiment, expressed asthe % cross section of the flow paths (passageways) versus the fullinside diameter of the compression spring coils, about 49% of theavailable cross-section inside of the compression spring coils isdivided into the four passageways.

FIG. 7A illustrates a view of aerosol valve 40 that shows the positionof compression spring 44 in relation to passageways 64, 66, 68, 70.Compression spring 44 is shown in FIG. 7A as fully-compressed (open), asthe spring would be when aerosol valve 40 is fully-actuated. FIG. 7B isan identical view to FIG. 7A, but with shading to clearly illustratethese components.

FIG. 8A illustrates another view of aerosol valve 40 to show theposition of compression spring 44 in relation to passageways 64, 66, 68,70. Compression spring 44 is shown as fully-compressed in FIG. 8A, asthe spring would be when aerosol valve 40 is fully-actuated. FIG. 8B isan identical view to FIG. 8A, but with shading to clearly illustratethese components.

FIG. 9 illustrates valve 40 in mid-stroke, which is an intermediate,short-lived position of the valve as the valve transitions from anunactuated (closed) position to its fully-actuated (open) position whenthe valve stem is pressed by the consumer to spray the product. Whilethe valve is in this intermediate position, the product formulation ispropelled upward primarily by primary flow path 60 through the center ofcompression spring 44. However, in this brief transition time, some ofthe product formulation is moving around spaces 45 between the coils ofcompression spring 44 in secondary flow path 62.

FIGS. 10 and 11 show a cross-section of valve 40 in its fully-actuatedposition. Valve stem 46 fully compresses compression spring 44, whichreduces or eliminates spaces 45 between the coils. Thus, as shownclearly in FIG. 11, at full-stroke, nearly all (or all) of the productformulation moves upward in aerosol valve 40 through the center ofcompression spring 44, which is shown as primary flow path 60. Primaryflow path 60 is shorter and less tortuous as compared with the flowpaths in existing aerosol valves (for example, as compared with theprimary flow path 30 in the prior art described above). This shorter,less tortuous flow path reduces the likelihood of agglomeration of thesolids in the product formulation, and reduces produce failures.

As shown in FIG. 11 (as well as in FIGS. 7A-7B and 8A-8B), the geometryof compression spring 44 and large passageways 64, 66, 68, 70 direct theingress of the product formulation to flow upward almost exclusivelyalong primary flow path 60 through the center of compression spring 44,and to exit the upper end of compression spring 44 still within thespace circumscribed by the spring coils.

Conversely, as also shown in FIG. 11, the interaction between valve stem46 and compression spring 44 when valve 40 is actuated allows verylittle or none of the product formulation to move upward via secondaryflow path 62, which is a path along the outside of compression spring 44and between the individual coils. Again, this is because there is littleor no space between individual coils when the aerosol valve is fullyactuated. Since there is much less of the product formulation movingalong this longer, tortuous (secondary) route, there is reducedincidence of agglomeration of solids in the flow paths and,consequently, fewer product failures.

In an exemplary embodiment, the product formulation of the presentdisclosure is a mixture of two types of media, such as a mixture of apowder (solids) and propellant.

EXPERIMENTAL

Testing the proposed aerosol valve with high-solids product formulationshas resulted in no recordable instances of failure of the product todispense throughout full-life testing. This is in contrast to laboratorytesting with known, existing aerosol valve designs that failed due toagglomeration with a difficult, high-solids formulation that showed apropensity to agglomerate.

A method of using the free flow aerosol valve described above fordelivery of high-solids product formulations is also provided. Themethod uses the aerosol valve having shorter flow paths, fewer directionchanges, and larger passageways as compared with existing aerosol valvesto minimize agglomeration of solids in the flow paths and reduce productfailures due to, for example, blockage of flow paths.

As used in this application, the word “about” for dimensions, weights,and other measures means a range that is ±10% of the stated value, morepreferably ±5% of the stated value, and most preferably ±1% of thestated value, including all subranges therebetween.

It should be understood that the foregoing description is onlyillustrative of the present disclosure. Various alternatives andmodifications can be devised by those skilled in the art withoutdeparting from the disclosure. Accordingly, the present disclosure isintended to embrace all such alternatives, modifications, and variancesthat fall within the scope of the disclosure.

1. An aerosol valve for spraying a product formulation from a container,comprising: a mounting cup positioned on a top portion of the containerthat orients the aerosol valve in the container; a seal positioned onthe mounting cup; a dip tube connected to a reservoir of the productformulation in the container; a valve stem housing positioned below themounting cup and adjacent to the seal; a valve stem comprising: a valvestem aperture; a center hole; and a valve stem body, wherein the valvestem has a bottom portion that is shaped to form a flow passagewaythrough which the product formulation flows when the aerosol valve isactuated; a compression spring positioned in the valve stem housingadjacent the valve stem and contacting the valve stem at a contactpoint, the compression spring comprising: a spring coil; a space betweenadjacent spring coils; and a center space formed interior to andcircumscribed by the spring coils with a center space diameter, whereinwhen the aerosol valve is actuated by pressing on the valve stem, theproduct formulation in the reservoir flows upwardly under pressurethrough the dip tube and directly into and through the center space ofthe compression spring, is deflected around the outside of the valvestem body, enters the valve stem aperture and flows into the center holeto spray the product formulation outside of the container, therebyforming a primary flow path for spraying the product formulation,wherein the primary flow path is shorter and has fewer abrupt changes inflow direction than a flow path of a conventional aerosol valve, therebyreducing resistance and back pressure to flow of the product formulationthrough the aerosol valve, and wherein the primary flow path has fewerloci at which the product formulation can agglomerate and impede theflow of the product formulation before reaching the valve stem apertureas compared with a conventional aerosol valve, thereby reducingincidence of blockages in the primary flow path, and reducing a productfailure rate of the aerosol valve.
 2. The aerosol valve according toclaim 1, wherein the bottom portion of the valve stem is shaped to formtwo or more flow passageways.
 3. The aerosol valve according to claim 2,wherein the bottom portion of the valve stem is shaped to form four flowpassageways, and wherein the flow passageways are oriented perpendicularto each other.
 4. The aerosol valve according to claim 1, wherein theflow passageway has a large cross-section area to further reduceresistance to flow of the product formulation through the aerosol valve,and further reduce agglomeration of the product formulation.
 5. Theaerosol valve according to claim 1, wherein the cross section of theflow passageway comprises from about 44% to about 54% of the centerspace diameter.
 6. The aerosol valve according to claim 1, wherein thevalve stem body is a thinned valve stem body having a smallercross-section than a conventional valve stem body, and wherein thethinned valve stem body causes less deflection of the productformulation around the valve stem body than a conventional valve stemand reduces the length of the primary flow path.
 7. The aerosol valveaccording to claim 6, wherein the thinned valve stem body furtherreduces resistance to flow of the product formulation through theaerosol valve, and further reduces agglomeration of the solids in theproduct formulation.
 8. The aerosol valve according to claim 1, whereinthe primary flow path is a non-tortuous flow path.
 9. The aerosol valveaccording to claim 1, further comprising a secondary flow path of theproduct formulation passing through the spaces between the spring coilsof the compression spring.
 10. The aerosol valve according to claim 9,wherein the amount of the product formulation flowing in the primaryflow path exceeds the amount of the product formulation flowing in thesecondary flow path.
 11. The aerosol valve according to claim 9, whereinthe amount of the product formulation flowing on the primary flow pathis about 100% and the amount of the product formulation flowing on thesecondary flow path is about 0% when the aerosol valve isfully-actuated.
 12. The aerosol valve according to claim 1, wherein thespring coils are fully-compressed to eliminate all spaces therebetweenwhen the aerosol valve is fully-actuated, and all of the productformulation flows upward through the aerosol valve by the primary flowpath.
 13. The aerosol valve according to claim 1, wherein the springcoils are fully-compressed to eliminate all spaces therebetween when theaerosol valve is fully-actuated, eliminating recirculation flow andreducing resistance and back pressure to the flow of the productformulation through the aerosol valve, and reducing the number of lociat which the product formulation can agglomerate and impede the flow ofthe product formulation.
 14. The aerosol valve according to claim 9,wherein the product formulation flows upward through the aerosol valveby both the primary flow path and the secondary flow path when the valvestem is only partially actuated.
 15. The aerosol valve according toclaim 1, wherein the seal is a flexible material that is positionedbetween the mounting cup and the valve stem housing, and wherein theseal is slightly deformed when the valve stem pressed to actuate theaerosol valve.
 16. The aerosol valve according to claim 1, wherein theproduct formulation comprises a mixture of a chemical composition and apropellant.
 17. The aerosol valve according to claim 16, wherein thechemical composition comprises a powder.
 18. The aerosol valve accordingto claim 1, wherein the product formulation a high-solids productformulation.
 19. A method of using an aerosol valve for spraying aproduct formulation from a container, comprising: depressing a valvestem so that a valve stem aperture moves away from a seal positioned ata mounting cup until the product formulation flows from the containerunder pressure directly into and through a center space of a compressionspring, passes above the compression spring and is deflected around anoutside of a valve stem body, enters the valve stem aperture, flows intothe valve stem, and sprays from the valve stem; and releasing the valvestem to stop spraying the product formulation.
 20. An aerosol valve forspraying a product formulation from a container, comprising: a mountingcup positionable on the container; a seal on the mounting cup; a valvestem movable with respect to the seal between a sealed position and anunsealed position, the valve stem having a valve stem aperture and adispensing hole, the dispensing hole being in fluid communication withthe container via the valve stem aperture in the unsealed position, thedispensing hole not being in fluid communication with the container viathe valve stem aperture in the sealed position; a bottom portiondepending from the valve stem below the valve stet aperture, the bottomportion having a spring contact point and a plurality of flowpassageways; and a coil spring having a top end in contact with thevalve stem at the spring contact point so that the end is below theplurality of flow passage ways to define a primary flow path through acenter of the coil spring, over the top end of the spring, and into theplurality of flow passage ways.